Cost-Effectiveness Analysis of Fulvestrant 500 mg in Endocrine Therapy-Naïve Postmenopausal Women with Hormone Receptor-Positive Advanced Breast Cancer in the UK

Introduction The selective estrogen receptor degrader fulvestrant is approved for the first-line treatment of postmenopausal patients with hormone receptor-positive (HR+), locally advanced or metastatic breast cancer who have not received prior endocrine therapy. We evaluated the cost-effectiveness of fulvestrant versus comparator treatments in endocrine therapy-naïve patients with locally advanced or metastatic breast cancer. Methods A three-health-state (progression free, progressed disease, and death) partitioned survival model from the UK National Health Service and Personal Social Services perspective was developed to extrapolate study data for the cumulative probability of progression-free survival and overall survival to a lifetime (30-year) horizon. Relative comparator data were derived from a systematic literature review-informed network meta-analysis. Sensitivity analyses were applied to assess the impact of uncertainty in the parameter input values on the results. Results Over a lifetime horizon (30 years), the incremental cost (British pounds sterling) per patient associated with fulvestrant treatment was £18,867 versus anastrozole, £23,097 versus letrozole, and £17,131 versus tamoxifen, with incremental quality-adjusted life-years of 0.55, 0.77, and 0.76, respectively, and incremental cost-effectiveness ratios of £34,109, £29,827, and £22,532, respectively. The largest difference in costs between fulvestrant and the comparators was related to treatment costs. Conclusions Results suggest that fulvestrant could potentially be a cost-effective option compared with other endocrine monotherapies (anastrozole, letrozole, and tamoxifen) for treating endocrine therapy-naïve, postmenopausal women with HR+, locally advanced or metastatic breast cancer.